This invention relates generally to friction clutches having a cylindrical housing drum, and more particularly relates to clutches with a plurality of slots engaged by one or more clutch disks, and in which the frictional elements engage at a predetermined speed of rotation of a power shaft.
Centrifugal friction clutches which engage at a predetermined rotational speed are particularly useful in combination with internal combustion engines which tend to stall under starting load conditions, by delaying engagement until the engine is operating at a sufficiently high speed to produce enough torque to prevent stalling. One such centrifugal clutch includes a number of plates and discs which move into frictional engagement by pressure exerted by pivoting of weights arranged next to the plates and discs. Such centrifugal friction clutches are also particularly useful in connection with small displacement internal combustion engines such as are used in go-carts, a demanding application of such a clutch in which any unnecessary size and weight can be a disadvantage. Centrifugal clutches are also known in automatic multispeed transmissions, but such transmissions add a considerable amount of size and weight to a small vehicle, and go-carts or one-quarter midget racing vehicles typically are not equipped with transmissions. It is therefore necessary for the clutch to be continually engaged and disengaged.
In such a centrifugal clutch, as the clutch is operated the motion of the inner components of the clutch typically abrades the inside of the cylindrical housing drum of the clutch, requiring replacement of the housing drum and rebuilding of the clutch. In order to combat the problem of wear of the clutch housing, one conventional type of clutch provides a wear shoe for placement within a slotted portion of the clutch housing. Another conventional type of clutch provides wear resistant stop blocks which prevent wear when the clutch pads are expended. It would be desirable to provide a centrifugal clutch with replaceable wear clips to serve as replaceable wear surface and wear indicators that will incur wear from the inner components of the clutch instead of the cylindrical drum during operation of the clutch, and that can be checked at regular intervals and replaced as required, in order to extend the normal useful life of the centrifugal clutch. The present invention meets these needs.
Briefly, and in general terms, the present invention provides for a wear clip for a clutch which acts as a replaceable wear surface and wear indicator for the cylindrical housing drum of the clutch. The wear clip of the invention is a U-shaped clip that may be formed from a wear-resistant material, such as carbon steel or aluminum. The cylindrical housing drum of the clutch includes slots, and a wear clip of the invention may be placed in each slot and checked at regular intervals of operation of the clutch and replaced as necessary in order to reduce abrasion of the cylindrical housing drum by the inner components of the clutch and extend the useful life of the clutch.
The present invention accordingly provides for an improvement in a clutch for transmission of torque from a rotating input connector means for supplying rotational power to an output connector means for receiving the rotational power, the clutch having frictional surfaces adapted to be engaged at a predetermined engagement speed of rotation of the input connector means, the clutch including a cylindrical housing drum having a plurality of slots, a plurality of clutch plates disposed within the cylindrical housing drum operatively engaged with the input connector means, the plurality of clutch plates including at least one clutch disk having a plurality of flanges engaging the plurality of slots of the cylindrical housing drum, respectively. The improvement in the clutch comprises a plurality of U-shaped wear clips disposed in said slots of said cylindrical housing drum, wherein each of said U-shaped wear clips comprises first and second parallel legs and a middle portion, the first and second legs extending in a perpendicular direction from the middle portion; and first and second pairs of flanges extending outwardly from said first and second legs, respectively, perpendicular to the legs, and forming an outwardly facing U-shaped channel on each of said first and second legs, each of said first and second pairs of flanges forming an interference fit with the plurality of slots of the cylindrical housing drum when the wear clips are inserted in the slots. In a preferred embodiment, the clutch is a centrifugal clutch. In one preferred aspect, the wear clips are formed from wear-resistant material, such as carbon steel or aluminum.